initial

src/main/java/io/swtc/proccessing/AutoGainProcessor.java

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+package io.swtc.proccessing;
+
+public class AutoGainProcessor {
+
+    public float[] calculateAutoGains(int[] pixels) {
+        long rSum = 0, gSum = 0, bSum = 0;
+
+        int step = 8;
+        int sampledCount = 0;
+
+        for (int i = 0; i < pixels.length; i += step) {
+            int pixel = pixels[i];
+            rSum += (pixel >> 16) & 0xFF;
+            gSum += (pixel >> 8) & 0xFF;
+            bSum += pixel & 0xFF;
+            sampledCount++;
+        }
+
+        if (sampledCount == 0) return new float[]{1f, 1f, 1f};
+
+        float rAvg = (float) rSum / sampledCount;
+        float gAvg = (float) gSum / sampledCount;
+        float bAvg = (float) bSum / sampledCount;
+
+        float grayAvg = (rAvg + gAvg + bAvg) / 3.0f;
+
+        if (grayAvg < 1.0f) return new float[]{1.0f, 1.0f, 1.0f};
+
+        return new float[]{
+                Math.min(2.0f, grayAvg / rAvg),
+                Math.min(2.0f, grayAvg / gAvg),
+                Math.min(2.0f, grayAvg / bAvg)
+        };
+    }
+}